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NAME
eqn - typeset mathematics
SYNOPSIS
eqn [ file ] ...
DESCRIPTION
Eqn is a troff (I) preprocessor for typesetting mathematics
on the Graphics Systems phototypesetter. Usage is almost
always
eqn file ... | troff
If no files are specified, eqn reads from the standard
input. A line beginning with ``.EQ'' marks the start of an
equation; the end of an equation is marked by a line begin-
ning with ``.EN''. Neither of these lines is altered or
defined by eqn, so you can define them yourself to get cen-
tering, numbering, etc. All other lines are treated as com-
ments, and passed through untouched.
Spaces, tabs, newlines, braces, double quotes, tilde and
circumflex are the only delimiters. Braces ``{}'' are used
for grouping. Use tildes ``~'' to get extra spaces in an
equation.
Subscripts and superscripts are produced with the keywords
sub and sup. Thus x sub i makes $x sub i$, a sub i sup 2
produces $a sub i sup 2$, and e sup {x sup 2 + y sup 2}
gives $e sup {x sup 2 + y sup 2}$. Fractions are made with
over. a over b is $a over b$ and 1 over sqrt {ax sup 2
+bx+c} is $1 over sqrt {ax sup 2 +bx+c}$ . sqrt makes
square roots.
The keywords from and to introduce lower and upper limits on
arbitrary things: $lim from {n-> inf} sum from 0 to n x sub
i$ is made with lim from {n-> inf} sum from 0 to n x sub i.
Left and right brackets, braces, etc., of the right height
are made with left and right: left [ x sup 2 + y sup 2 over
alpha right ] ~=~1 produces $left [ x sup 2 + y sup 2 over
alpha right ] ~=~1$. The right clause is optional.
Vertical piles of things are made with pile, lpile, cpile,
and rpile: pile {a above b above c} produces $pile {a above
b above c}$. There can be an arbitrary number of elements
in a pile. lpile left-justifies, pile and cpile center,
with different vertical spacing, and rpile right justifies.
Diacritical marks are made with dot, dotdot, hat, bar: x dot
= f(t) bar is $x dot = f(t) bar$. Default sizes and fonts
can be changed with size n and various of roman, italic, and
bold.
Keywords like sum ( sum ) int ( int ) inf ( inf ) and short-
hands like >= (>=) -> (->), != ( != ), are recognized.
Spell out Greek letters in the desired case, as in alpha,
GAMMA. Mathematical words like sin, cos, log are made Roman
automatically. Troff (I) four-character escapes like \(bs
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() can be used anywhere. Strings enclosed in double quotes
"..." are passed through untouched.
SEE ALSO
A System for Typesetting Mathematics (Computer Science Tech-
nical Report #17, Bell Laboratories, 1974.)
TROFF Users' Manual (internal memorandum)
TROFF Made Trivial (internal memorandum)
troff (I), neqn (I)
BUGS
Undoubtedly. Watch out for small or large point sizes -
it's tuned too well for size 10. Be cautious if inserting
horizontal or vertical motions, and of backslashes in gen-
eral.
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